The present invention relates to fabrication processing techniques of semiconductor devices and related devices. In particular, it relates to techniques for performing film deposition using fluids that have an organic metal as the main component (organometallic fluids).
In recent years, as improvements in the integration and miniaturization of the semiconductor device progresses, there has been a steady shift from the present sub-half-micron range to the sub-quarter-micron range. In this quest to develop the next generation of semiconductor devices, film deposition techniques are exceedingly important.
In response to demands for improvements in integration and further miniaturization, switching from aluminum-based materials to copper-based materials being used as interconnect material or line material is under consideration. Presently, metal-organic chemical vapor deposition (MOCVD), which is performed by vaporizing an organic metal (usually fluid at room temperature and under normal pressure), for example (hfac)Cu+1(tmvs), introducing it to the process chamber, and depositing a film by causing a pyrolytic decomposition reaction to occur on the wafer being held in said process chamber, is put into affect.
Such conventional MOCVD processes provide superb step coverage and are extremely effective in the fabrication of very thin films. However, with these MOCVD processes, problems developed such as the effective usage of the organic metal being extremely poor due to the organic metal vaporized inside the chamber being released out of the chamber driven by the release pump. Furthermore, in regards to the organic metal not released outside the process chamber, problems also developed where film could not be formed in the desired locations on the to-be-processed body because it was in its gas state. In particular, in cases such as those mentioned above where high cost materials such as (hfac)Cu+1(tmvs) are used, when the organic metal is used with low effectiveness, there is a large increase in costs.
The present invention takes the above information into consideration and aims to provide a film deposition process and apparatus, which use organometallic fluids, wherewith the organic metal may be used with high effectiveness, and which may accurately apply organometallic fluid onto the to-be-processed body.
In order to achieve the above objectives, the inventors discovered that it is possible to cause a pyrolytic decomposition reaction using heat even when the organometallic fluid is in its fluid state. In other words, film deposition is possible even if the organometallic fluid is not vaporized, and the present invention was first formulated based on these findings.
Here, it is possible to consider applying the organometallic fluid while heating the wafer; however in this situation, the possibility of the organometallic fluid vaporizing increases making it difficult to use the organic metal more effectively, and it is difficult to obtain an accurate application of organometallic fluid onto the to-be-processed body.
Therefore a film deposition method, according to the present invention, is characterized by comprising: a first step of preparing an organometallic fluid that has organic metal as a main component, which precipitates a film deposition material using a pyrolytic decomposition reaction; a second step of applying said organometallic fluid onto a to-be-processed body by bringing a fluid containing body, which contains said organometallic fluid, into contact with said to-be-processed body at a temperature within the non-reactive range of said organic metal; and a third step of heating said to-be-processed body to a predetermined temperature, and causing the pyrolytic decomposition reaction of said organic metal in said organometallic fluid that is applied onto said to-be-processed body to occur so as to form a film on said to-be-processed body.
With this method, after the organometallic fluid has been applied to the to-be-processed body at a temperature within the non-reactive range of the organic metal, a film may be formed on the to-be-processed body by heating the to-be-processed body to a predetermined temperature. In particular, with this invention, since the organometallic fluid is applied onto the to-be-processed body at a temperature within the non-reactive range of the organic metal, the organometallic fluid does not vaporize. Besides, since the application of organometallic fluid onto said to-be-processed body is performed by bringing an application fluid containing body into contact with said to-be-processed body, no organometallic fluid is wasted, and together with being able to use the organic metal more effectively, application of the organometallic fluid onto the to-be-processed body can be performed with accuracy.
It is noted here that the organometallic fluid may comprise solely an organic metal, or it may comprise a mixture of an organic metal and a solvent. It is also noted that in this specification, xe2x80x98mixed fluidxe2x80x99 may refer to cases where the organic metal is completely dissolved or it may refer to cases where part of it is suspended. Furthermore, xe2x80x98application fluid containing bodyxe2x80x99 may mean a sponge, a brush, or the like that absorbs, the organometallic fluid, or something with a surface to which the organometallic fluid may be applied.
Furthermore, when the to-be-processed body is a wafer, it is preferable that during application of the organometallic fluid onto said wafer, the outer rim of the wafer be covered by a mask. In this case, unnecessary application of organometallic fluid onto the outer rim of the wafer may be prevented.
Furthermore, it is preferable that the film deposition apparatus for executing the above method comprises a supply means for supplying an organometallic fluid, which has an organic metal as a main component and which precipitates film deposition material using a pyrolytic decomposition reaction; an application means for applying the organometallic fluid that is supplied by said supply means onto a to-be-processed body; and a heating means for heating to a predetermined temperature the to-be-processed body to which is applied the organometallic fluid by said application means; wherein said application means is outfitted with a fluid containing body, which is capable of containing said organometallic fluid and capable of coming into contact with and separation from said to-be-processed body.